Objective To explore application value of spiral CT in the diagnosis and disease classification of acute pancreatitis. Methods A retrospective analysis of clinical data was carried out in 110 patients with acute pancreatitis treated in our hospital from August 2013 to August 2015 who were selected as the research objects, Balthazar CT plain scanning was used as the reference to carry out morphological change scores, CTSI scores was carried out combined with necrosis, and determined disease severity. Results Hospitalized time of mild and moderate patients were (9.6±2.3)d, (21.5±5.4) days, no deaths, good prognosis; hospitalization time of severe patients was (40.2±6.8) days, death rate was 20.0%, prognosis was significantly worse than mild and moderate patients (P<0.05). Main performances of patients with acute pancreatitis in early stage were pancreatic volume increase, pancreatic duct dilation, CT value was about 30HU, density was lower than normal pancreas. With disease aggravated, fatty space near pancreas dribbled away, prerenal fascia bodiness, pancreatic profile blur. Performances of edema calidum or necrosis occurred in pancreas were pancreas low density shadow (CT value 10~20HU). After enhancement scanning, mild enhancement occurred in edema zone, no enhancement in necrotic area, performance was low density. Air fluid level could be seen in patients with necrotic pancreatitis, performance of haemorrhage was high density. Conclusion Clinical manifestation of acute pancreatitis is complicated, progression disease is fast, application of spiral CT can display pancreatic lesion location, extent of disease and degree accurately, understand lesion absorption, degeneration condition, provide basis for clinical treatment via qualitative diagnosis and somatotype of acute pancreatitis, so that patients can get effective treatment as early as possible, avoid progression disease, promote prognosis improvement.